The present invention relates to template control for the relative moment between material and tool (needle) on processing machines, particularly sewing machines, in which a template can be adjusted to the different shape and/or size of a workpiece (garment). A roller is pressed against this template which is equipped with a gear pinion located and driven coaxially. This pinion meshes with teeth adaptable to the shape of the template in order to guide the roller without slipping along the template.
It is the object of the present invention to provide a template for sewing machines, thus facilitating the adjustment to different garment (material) contours and assuring the safe non-slip roll-off of the roller pressed against the template.
From the German Utility Pat. No. 1 998 372, there is already known a template for sewing parts of similar garments of different size whose guide is moved through a guide groove corresponding to the contour of the seam in a base plate of the template and along it by means of a gear rack, with the teeth located on various portions of the guide groove on parts whose position relative to the base plate is variable. This template provides a non-slip roll-off of the scanning means, but a change of the garment shape can be carried out only by proper change of the guide groove and the gear rack so that the template is suited only for the sewing of similar garments of different length.
There is also known from the German Laid-Open Document 21 50 197 a template for use in sewing machines for sewing garments of different shape and/or size and which is located on a support plate and is traced by a driven roller pressed against the template. The template comprises a large number of individual segments, displaceably fastened to the support plate and forming the contact surface for the driven magnet roller. At those points on the templates where the magnet roller undergoes an angular change in direction there are toothed segments meshing with a gear pinion located coaxially with the magnet roller and driven by it, in order to prevent idling of the roller at these locations.
This known template makes it possible to process garments of different length and, within certain limits, different shape without replacing (interchanging) template parts. However, a slip of the magnet rollers due to the absence of teeth extending throughout the entire profile of the template cannot always be prevented, especially when the mass to be moved by means of the magnet roller is large.
From the German Laid-Open Document No. 2403945 there is already known a driven gear pinion for guiding a sewing machine along a template conforming to the seam contour; this template comprises mutually displaceable and toothed portions located in at least two planes; this template is contacted under pressure by the gear pinion whose drive shaft mounts an auxiliary gear pinion which can be rotated from its normal position in either direction by half a tooth width, and is turned together with the gear pinion. The toothed template causes a nonslip tracing of the template profile, and makes possible a continuously variable adjustment to the different garment length. However, any change to another shape requires the preparation of a toothed template depending on the required shape.
It is the object of the present invention to provide a template control of the initially-mentioned type and which makes possible not only a nonslip travel of the roller pressed against the template, but also a continuously variable adjustment to another garment shape without replacing template parts.
Another object of the present invention is to provide a template control of the foregoing character which is simple in construction and may be economically fabricated.
A further object of the present invention is to provide a template control, as described, which may be readily maintained in service, and which has a substantially long operating life.